Depending on the operating mode, very high temperatures can prevail in the cooking chambers of cooking appliances. Some cooking appliances also provide, among other things, a cleaning of the cooking chamber via a pyrolysis method. Then, the cooking chamber is heated to 450° C. or even hotter in order to burn contaminants adhering to the cooking chamber walls.
So that hot or excessively hot air cannot escape from the cooking chamber in a cooking process, and in particular also in a pyrolysis process, and in order for the outer side of the cooking chamber door not to exceed a critical temperature, the doors must be adequately insulated.
Sufficient insulation in glass doors, or cooking chamber doors including a viewing window, is achieved via a multi-pane construction. In such a multi-pane construction, a satisfactory insulation is achieved by a plurality of panes disposed parallel to one another and spaced apart from one another, so that no risk arises for a user.
For a satisfactory insulation, it is important that the panes are intact and in particular that the inner pane is not damaged. Thus, a cooking appliance having a cooking chamber door with a multi-pane construction should not be used if a pane is defective.
In order to prevent the operation of a cooking appliance with a broken pane, attempts have been made to minimize the risk of a defective pane. For this purpose, panes made of laminated glass have been used in order to avoid a leak of the inner pane in the event of a defect. By means of a thermostat, it could also be verified via the temperature profile in the cooking chamber whether the panes of the cooking chamber door are intact. To date, a reliable solution could, however, not be found. Thus, under certain circumstances it can happen that a cooking appliance can be operated despite having a defective pane.